In U.S. Pat. No. 4,594,490 issued on June 10, 1986, to Harold E. McCullough, there was disclosed a terminal pin shorting switch apparatus which includes an electrical shorting spring member 12 positioned within chamber 1001 of a housing component 100. The spring member 12 is comprised of a common member 120 formed at each end into generally C-configured sections 121, 122 extended into cantilever springs 123, 124. The tip contact ends 125, 126 of each cantilever spring are normally in engagement with a pair of terminal pins 3. An actuating member 11 comprised of a pivotal member 111 when rotated moves a cam surface 1101 against both cantilever springs so as to disengage the tip contact ends from the pair of terminal pins.
In U.S. Pat. No. 4,393,283 issued on July 12, 1983, to Toru Masuda, there is disclosed a jack case 3 for receiving a plug 6 which includes a detachable slide switch 12. The slide switch is operated by means of a movable contact strip 4 that engages the plug. When the plug 6 is not inserted into the jack case 3, the clip holder 19 of the slide switch 12 is urged by means of the free end portion 4d of the contact strip 4 to the right side position of FIG. 1, thereby bringing first and second terminals 17a and 17b into connection through means of clips 18 mounted upon the clip holder 19. On the other hand, upon insertion of a plug into the jack case, the clip holder 19 is caused to slide to the left side position so as to render engagement of second and third terminals 17b and 17c.
Neither of these two above-identified patents discloses a ground start switch like that of the present invention which permits momentarily shorting a central office line to a ground potential when a private branch exchange is inoperative. This is accomplished by means of a switch actuator mechanism which is adapted to be mounted onto a modular duplex adapter having a pair of jack terminals. A conductive member is attached to the switch actuator mechanism. The switch actuator mechanism includes a resilient lever arm which is depressible for causing engagement of the conductor member with the pair of jack terminals so as to electrically short them together.